Smoke-consuming furnace.



No. 754.999. PATEN'IED MAR. 22, 1904.

J. B. HARRIS. SMOKE GONSUMING FURNAGE.

APPLICATION FILED MAR. 27, 1903. no MODEL. I 4 sums-sans! 2.

'PATENTED MAR. 22, 1904.

J. B. HARRIS. SMOKE GONSUMING FURNACE.

APPLIOATION FILED MAR. 27, 1903.

4 SHEETS-3811331 4.

NO MODEL.

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UNITED STATns Patented March 22, 1801.

ATENT FFICE.

SMOKE-CONSUMING FURNACE.

SPECIFICATION forming part of Letters Patent No. 754,999, dated March1904.

Application filed March 27, 1903.

To all whom it may concern:

Be it known that I, J OHN BROWN HARRIS, a citizen of the United States,and a resident of Nashville, in the count-y of Davidson and State ofTennessee, have invented a new and Improved Smoke-Consuming Furnace, ofwhich the following is a full, clear, and exact description.

The invention relates to smoke-consuming furnaces such as shown anddescribed in the Letters Patent of the United States N 0. 721,698,granted to me -March 3, 1903.

The object of the present invention is to provide a new and improvedsmoke-consuming furnace arranged to insure a complete combustion of thefuel in the fire-box and combustion-chamber by the introduction ofheated air into the front top portion of the fire-box and into thecombustion-chamber at the bridge-wall.

-The invention consists of novel features and parts and combinations ofthe same, as will be more fully described hereinafter and then pointedout in the claims.

. A practical embodiment of the inventioni represented in theaccompanying drawings,

forming a part of this specification, in which similar characters ofreference indicate corresponding parts in all the views.

Figure 1 is a longitudinal sectional elevation of the improvement asapplied to a horizontal tubular boiler, the section being on the line 11 of Fig. 2. Fig. 2 is a transverse section of the same on the line 2 2of Fig. 1. Fig. 3 is a similar view of the same on the Fig. 1 is alongitudinal sectional elevation of the improvement as applied to awater-tube boiler, the section being on the line 4 40f Fig. 5. Fig. 5 isa crosssection of the same on the line 5 5 of Fig. 1, and Fig. 6 is asimilar view of the same on the line 6 6 of Fig. 4:.

A boiler A is set in the usual manner in brickwork B containing afire-box C, having a grate D, below which is arranged an ash-pit E,access to which and to the fire-box C is had by suitable doors E and C.At the rear end of the fire-box C is arranged a bridge-wall F, havingits top in an inverted-arch shape and spaced from the under side of theboiler A to Serial No. 149,315. (No model.)

form a combustion-chamber Gr, the rear end of which leads to the rearend of the boilerA for heated gases to pass to and through the flues ofthe boiler A in ,a forward direction and to finally pass into a stack A.

In the front upper portion of the fire-box C is arranged an air-chamberH, formed by spaced concentric arches H and H extending from the sidewalls of the brickwork B, the top of the outer arch H being spaced fromthe under side of the boiler A to leave the latter unobstructed at thispoint, and thus maintain a full heating-surface of the boiler throughoutthe length thereof. The lower arch H extends above the door C, so as notto obstruct the entrance to the fire-box O.

In the air-chamber H are arranged air-retarding devices, preferably inthe shape of checker-bricks H to retard the air in the said chamber H toinsure heating thereof to a high degree previous to the heated airpassing into the fire-box above the burning fuel on the grate D.

i The inner end of the upper arch H projects a distance beyond the innerend of the lower arch H so that the heated air passing from the chamberH at the inner open end is guided end thereof, are connected withair-ducts I,

extending rearwardly in the side walls of the brickwork B, to lead tothe outer air at the back wall of the brickwork, and the rear ends ofthe said ducts I are adapted to be opened and closed by suitable hingeddoors J each connected by a chain J with a bell-crank lever J fulcrumedon the top of the brickwork B, and connected by a link J with anotherbell-crank lever J arranged on the front of the brickwork B, and thisbell-crank lever J 4 is provided with a depending handled chain or ropeJ 5 under the control of the operator. Thus when pulling the chains J 5the doors J are swung open, so as to allow air to pass through the ductsI into the heating-chamber H and from the latter into the fire-box, itbeing understood that the air during its passage through the ducts Ireceives a preliminary heating, and this heated air is heated to a veryhigh degree in the chamber H before it passes into the fire-box A.

A second air-chamber K is formed in the bridge-wall F, and this chamberleads to the inverted arched top of the bridge-wall, and on this top arearranged longitudinally-extending bricks K, spaced apart to formopenings K for the air to pass from the chamber K,through the saidopenings, into the combustion-chamber Gr. (See Fig. 3.) To the bottom ofthe chamber K leads a door K for the convenient removal of ashes andcinders that may fall into the chamber K through the openings K Into thechamber K also open the forward ends of air-ducts L, built on the innerface of the side walls of the brickwork B, and the rear ends of the saidducts L connect by branch ducts L in the back wall of the brickwork Bwith ducts L extending forwardlyin the side Walls of the said brickworkB. The forward ends of the ducts L are adapted to be opened and closedby doors N, similar to the doors J and under the control of the operatorby the employment of chains or ropes N, each of which is attached at oneend to a corresponding door and then extends upward over a pulley Njournaled on the top of-the brickwork B. The depending front end of thechain or rope N is adapted to be taken hold of by the operator, so thatthe latter on pulling the rope swings the corresponding door N into anopen position to allow atmospheric air to pass into the front end of theduct L to travel rearwardly therein and to finally pass by the branchduct L into the duct L to finally reach the air-chamber K in thebridge-wall F.

Now it will be seen that the air in its rearward and forward passage inthe ducts L L, and L receives a preliminary heating and a final heatingto a high degree in the chamber K to pass in this condition through theopenings K into the combustion-chamber G. In the latter are arrangedchecker-bricks O to somewhat retard the rearward flow of the smoke andgases and to cause a thorough intermingling of the air with the gases toinsure complete combustion. As indicated in Fig. 1, at the front end thechecker-bricks O are set in step form, so that the air and gas arecaused to travel in an upward direction toward the under side of theboiler A to thoroughly heat the same.

Now from the foregoing it will be seen that when the fuel is burning onthe grate D and the doors J and N are opened then air passes through theducts described into the airchambers H and K, and the heated air in thechamber H passes directly into the smoke and gases arising from the fuelon the burning-grate D, so as to insure combustion of the gases andreduction of the smoke, and the mixture in passing over the bridge-wallF comes in contact with a fresh supply of highly-heated air from thechamber K, and

this air is thoroughly mixed with the smoke and gases in thecombustion-chamber G, es-

pecially by the aid of the checker-bricks O, to

insure a complete combustion previous to the heated gases leaving thesaid combustionchamber and passing through the boiler A into thesmoke-stack A.

In water-tube boilers A as shown in Figs. 4, 5, and 6, the arrangementis similar to that above described in reference to the horizontaltubular boiler A, it being understood that the boiler A is set in theusual manner in the brickwork B and the heating-chamber H* is arrangedin the front upper portion of the fire-box C while the heating-chamber Kis arranged in the bridge-wall F, and the said chambers H and K* haveducts I and L, the

entrances to which are controlled by doors J and N, as plainly indicatedin Fig. 4. The checker-bricks O in the combustion-chamber G are arrangedin a slanting condition to conform to the inclination of theboiler-tubes, but have the same relation to the spaced bricks K formingthe outlet-openings K for the heated air from the heating-chamber K; butinstead of having the top of the bridge-wall F in an inverted-arch shapeit is perfectly straight, as will be readily understood by reference toFig. 6.

The operation is the same as above described in reference to thehorizontal tubular boiler, so that further description of the same isnot deemed necessary.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent 1. A smoke-consuming furnace, comprising a fire-box,air-chambers for delivering heated air to the smoke and gasesarisingfrom burning fuel in the fire-box, one of the air-chambers beingarranged in the front top portion of the fire-box and the other in thebridge-wall in the rear of the fire-box, an air-duct extending in theside wall of the furnace and leading from the said front air-chamber tothe rear end of the furnace and opening into the outer air, and a secondair-duet in the side wall of the furnace, leading from the bridge wallchamber to the rear of the furnace and to the front thereof and openinginto the outer air, as set forth.

2. A smoke-consuming furnace, comprising a fire-box, air-chambers fordelivering heated air to the smoke and gases arising from burning fuelin the fire-box, one of the air-chambers being arranged in the front topportion of the fire-box and the other in the bridgewall in the rear ofthe fire-box, air-ducts ex-- end of the furnace and opening into theouter air, as set forth.

3. In a smoke-consuming furnace, a firebox having a grate, anair-chamber in the front top portion of the fire-box and formed ofspaced arches, said chamber extending horizontally partially over thegrate, and air-ducts leading from the said chamber to the rear end ofthe furnace and opening into the outer air, as set forth.

4. In a smoke-consuming furnace, a firebox having a grate, anair-chamber in the front top portion of the fire-box and formed ofspaced arches, the upper one of which projects beyond the lower one,said chamber extending horizontally partially over the grate, andair-ducts leading from the chamber to the rear end of the furnace andopening into the outer air, as set forth.

5. In a smoke-consuming furnace, a firebox having a grate, anair-chamber in the front upper portion of the fire-box and formed ofspaced arches, the upper one of which pro jects beyond the lower one,said chamber extending horizontally partially over the grate, and filledwith retaining devices in the form of checker-bricks, air-ducts leadingfrom the chamber to the rear of the furnace and opening into the outerair, and doors for said ducts, under the control of the operator, as setforth.

6. A smoke-consuming furnace provided with a fire box, acombustionchamber, a bridge-wall in the rear of the fire-box, anairchamber in the bridge wall, bricks spaced apart on the top of thechamber, to form spaced top openings for the escape of the air from thesaid air-chamber into thesaid comthe check-bricks being arranged in stepform,

as set forth.

8. A smoke-consuming furnace provided with a fire-box, acombustion-chamber having retarding means therein, a bridge-wall in therear of the fire-box, an air-chamber in the bridge-wall, bricks spacedapart on the top of the chamber, to form spaced top openings for theescape of the air from the said air-chamber into the saidcombustion-chamber, and air-ducts opening into the said air-chamber andextending first rearwardly, along the side walls of the furnace, to thenconnect by branch ducts in the back of the furnace with longitudinalducts arranged in the side walls of the furnace, and opening to theouter air at the front of the furnace, as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN BROI/VN HARRIS.

Witnesses:

ADAM GEBI-IARDT, GRACE DAWSON.

